Spherical ball-bearing caster



Jan. 2', 1923.

mo CASTER. 1920.

SPHERI Fl LED Surf. 21

' which sisal-chads sinner srnvnns, or iirnmitocnnr, trains.

SPHEBICAL BALL-BEARING car-ans.

Application filed September .21, 1920Jg$erial No. 411,7531.

To all whomit may concern: 4

it known that I, SIDNEY EVENS, a citizen. of the United States residingat liiillinoc ret, county of l enobscot State or me, have invented acertain new and useul improvement in Spherical Ball-Bearing s, of whichthe iollowingis a specireference being had therein to the companymgdrawings.

The invention relates to an improvement in spherical ball-bearingcasters. The object oi the inven ion is to produce a sphern calball-bearing caster which will enable the sphere to rotate in anydirection with cientfreedom so that at no time will the sphere drag uponthe surface with which bears. it is especially intended for use inconnection with articles of furniture, such for instance as beds,tables, chairs, couches.

side-boards nianos etc... althou 'h it is well n a l 9 D adapted Ior usein connection with trucks and'with machinery where its peculiar taci tyof turning); in any direction would par tcular'ly adapt it for use.

The invention will be fully understood n the following; description whentalren in connection with the accompanying drawings and the novelfeatures thereof will be pointed out and clearly defined inthe claims atthe close or" thislspecification.

In the drawings, Fig. 1 is a view in elevation of a caster embodying theinvention connected with the leg of a piece of turniture.

Fig. 2 is a section on line 2-'-2 of Fig. 1. 3 is a section on line 33of Fig. 2. a is a plan view of the bulb around the balls for the bearingare to be assembled.

Fig. 5 is a sectional view showing a modified form of the deviceembodying the in- I vention.

Fig.6 is a section on line 6-6 of Fig. 5

Fig. 7 is a plan view ofthe bulb employed in the modified form ofdevice.

Referring now to the drawings, 1 represents the sphere which is mountedin a suitable holder embodying the invention having a spindle 2 which isadaptedto be engaged with a socket in a leg or foot-piece 3 of the pieceof furniture or other article with which the caster is to be employed.Connected with the spindle 2 is the head Zl of the holder men'iber,which has a downwardly extending shell portion 5, said shell portionbeing; formed with a chamber 6 which is circular in horizontal crosssection and has an arched top i. Below the chamber 6 the said shell hasa further downwardly extending annu-- lar portion which is of somewhatgreater di meter than the diameter of the sphere l. Detachably connectedwith said annular portion 8 is a clamping ring 9 which. is connectedwith the said annular portion 8 of the shell after the sphere l isintroduced within the shell the purpose oi"; said clamp beingto holdthesphere in place. The said clamping ring 9 preferably has a screwthreadedconnection 10 with the shell member 8 so that it-can be adjustable aswell as 7 detachable'to admit the sphere. The said clamping ring 9 iscurved inward towards its lower ends, so that the opening at the lowerend is of less diameter than the diamv eter of the sphere while thediameter of the '7 5 upper end of the ring is somewhat greater than thediameter of" the sphere. Thecontracted lower end of the ring should justbarely contact with the sphere throughout its periphery at some distancebelow' the center of the sphere, so as to holdit from falling-out andfrom rattling a round.,, butat the same time allowing it freedom of mo-vtion. i

bulb 11. as I have termed it, is secured, 5 centrally within the chamberof the shell 5, said bulb being of any suitable material. It is circularin plan view as shown in Figme a, and is concave on its under side andconvex on its upper side in vertical section-9 in all radial directionsand is concentric with the sphere 1 as shown in Figure 2. Its peripheryis also on'the arc ,ofga circle in vertical section, shown in Figure 2.The diameter of the bulb is sufficiently less than the diameter of thechamber 6 to form a space between the bulb 11 and the wall of thechamber 6, to receive the ball-bearings 12 which entirely surround thebulb. In order to close the bottom of the ball-bearing chamber betweenthe sphere and the shell 5, a ring 13 is screwed into the shell asshownat 14, said ring 13 having a concaved upper face 15 which followsthe curve of the con- The entire downward pressure oi? the art-iclesupported by the casters will be vertically downward upon the ballswhich rest upon the sphere within the space surrounded by the innerperiphery 16 of the ring 18. This set of bells which sustains the weightare errenged in a circular group on the under side the conceived undersurface of the bulb 11, so that the sphere 1 can i (ily roll in anydirection- As viewen in shows a central sectional there are shown of thewit the sphere, hot or ball genie-ht be as n" ny as could be enclosed inthe circle whose diameter equa the combined di- (.0 eineter of sin ofthe bells.

' The preferred means of securing the head l of the sl l to the bulbshown in Figconsist of El screw-threadedstein 12 e 2 1'4 which crewsinto the bulb, as shown in Figure iny other suitable form of connection,however, may be employed. Une other form is shown in Figures 5, 6 and 7,in which the bulb is connected with the inner periphery of the shell byfour thin pointed pieces 18 which project from the shell 5 radiallyinward into enge went with the bulb.

Preferably the bulb 1.1 is formed with e series of shallow grooves 19crossing one another in various directions on its surface as shown inFigure i, to aid the balls in running to the right and to the left ofthe spindle 20. These grooves should preferably all be curved on the arcof s circle, although they each other at various angles.

What I claim is 1. in combination with a spherical caster;

a mount therefor having a chamber above being concave 'ircnhir inhorizontal hula suspended in the id bulb being circus d in e end'convexon it of sufficiently less ban the chamber so that there ismed a:continuous ball bearing space erounc the bulb at the top and bottom andsides, the periphery of the bulb being conveii inverticnl section so hntthe bell psssoge'hns continnous curve frojrn the upper to the under sides well as around the periphery, and ball lrieerings filling said theballs on the under side oi? the the sort c of the sphere, .oe being oilyr ientheight and underside or the bulb end rec nioven'ient of thebells without any overlnoping oi the balls on one another. lncombination with a spherical caster,

a inount therefore having a chamber above the sphere, said chamber beingconcave in vertical section and circuler'in horizontal SGCUOYL; andhaving a bulb suspended in the middle of the chamber, said bulb beingcircular in plan viewnnd concave on its lower face and convex on itsupper faceye'nd being of chamber, so that there is formed a continuousbell lJGZIl'lIL space etthe top and bottom and edge oi the bulb and thewells of the ball bearing space being curved in all ports the upper faceof the bulb being formed with curved grooves to aid in guiding thecirculatory movement of the bells.

In testimony w iereof l age; my signature.

- SIDNE 1 STEVENS.

sufiiciently'less diameter than the-

